---
id: "CVE-2026-118626"
kind: "vulnerability"
aliases: ["CVE-2026-118626"]
title: "MLflow Tracking Server: missing authorization lets authenticated users escalate privileges"
severity: "medium"
cvss: 5.4
epss: null
exploited: false
status: "open"
category: "ai-tooling"
products: [{"name": "mlflow", "fixed": ["3.16.0"], "affected": "< 3.16.0", "ecosystem": "pypi"}]
ecosystems: []
tags: ["ai-tooling", "ml-platform", "mlflow", "python", "self-hosted"]
not_affected_if: ["default-config", "fixed-3.16.0", "no-authenticated-users", "single-user"]
published_at: "2026-11-04T00:17:23+00:00"
first_seen_at: "2026-11-04T00:46:16+00:00"
updated_at: "2026-11-04T00:49:32+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118626", "first_seen_at": "2026-11-04T00:46:16+00:00"}, {"source": "analyst", "url": null, "first_seen_at": "2026-11-04T00:49:32+00:00"}]
---

# MLflow Tracking Server: missing authorization lets authenticated users escalate privileges

MLflow's tracking server has a missing authorization check in its request handler configuration, so a logged-in user can reach functions meant for higher-privileged users. An attacker with a valid account can gain access to resources normally protected from them.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- pypi:mlflow affected < 3.16.0 fixed 3.16.0

## How to check

- Run `pip show mlflow`; versions below 3.16.0 are affected per ZDI (lower bound unknown).
- You are exposed only if you run the tracking server with the built-in basic-auth app (`mlflow server --app-name basic-auth`) and have non-admin users. Check whether the Issue REST routes (/mlflow/issues, /mlflow/issues/search) are reachable by users without permission on the experiment.

## Fix

Upgrade MLflow to 3.16.0 or later (per ZDI-26-842; the linked PR #25067 was still open in the page I read, so the release itself is not confirmed from MLflow's own page).

## Timeline

- 2026-11-04T00:46:16+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-118626
- 2026-11-04T00:49:32+00:00 analyst — ZDI-26-842 says fixed in 3.16.0 and links PR #25067 (basic-auth: gate issue routes on experiment permission); PR page showed state open, so fix not verified against MLflow's release. Affected lower bound unknown. No exploitation or PoC seen. Nothing marked verified (ZDI is a third party).

## Documents

- [advisory] ZDI-26-842 MLflow Tracking Server Issues Missing Authorization Privilege Escalation https://www.zerodayinitiative.com/advisories/ZDI-26-842/
- [fix] mlflow PR #25067 [3/6] basic-auth: gate issue routes on experiment permission https://github.com/mlflow/mlflow/pull/25067

## From the sources

MLflow Tracking Server Issues Missing Authorization Privilege Escalation Vulnerability. This vulnerability allows remote attackers to escalate privileges on affected installations of MLflow. Authentication is required to exploit this vulnerability.

The specific flaw exists within the configuration of the BEFORE_REQUEST_HANDLERS. The issue results from the lack of authorization prior to allowing access to functionality. An attacker can leverage this vulnerability to escalate privileges to resources normally protected from the user. Was ZDI-CAN-32108.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_